Jeep Garage  - Jeep Forum

Jeep Garage - Jeep Forum (http://www.jeepgarage.org/forums.php)
-   Engine Performance/Intake/Exhaust (http://www.jeepgarage.org/f183/)
-   -   Another DIY CAI (http://www.jeepgarage.org/f183/another-diy-cai-44132.html)

SweetWilliam 07-01-2012 06:19 PM

Another DIY CAI
 
Owned my 05 for a couple weeks and have been doing a lot of reading on here and other places for info on this thing. I have had severl XJ's over ther years and loved them but nothing like a Hemi powered WK. I'm driving around 150 miles a day right now and this thing has reminded me that driving on road can be a little fun also.

Anyways, all this fascination with CAI's had me reading and starving for real information. I've done a lot of tuning on race quads and bikes on a Dyno Jet dyno with AFR meter and learned bunches about how the claims of manufacturers are way inflated, totally unrealistic, or skewed toward absolute highest number with no regard for the rest of the power band. Not to mention the crazy prices. With no dyno numbers that I can find directly comparing CAI's against each other or the stock set up, just looking at them, and again the totally ridiculous prices, I starting searching. Then yesterday I pulled intake stuff apart and did a little "drinkin and thinkin". After pancakes and coffee this morning I went for a walk thru Home Depot.

This is the result. I'm sure I'm not the first one to try it.

http://i54.photobucket.com/albums/g1...liam1/wka9.jpg

http://i54.photobucket.com/albums/g1...lliam1/WK2.jpg

http://i54.photobucket.com/albums/g1...liam1/WKA4.jpg

http://i54.photobucket.com/albums/g1...liam1/WKA5.jpg

http://i54.photobucket.com/albums/g1...liam1/WKA7.jpg

http://i54.photobucket.com/albums/g1...liam1/WKA8.jpg

Madanio24 07-01-2012 06:51 PM

Re: Another DIY CAI
 
Cool pictures but i wouldnt go in any puddles deeper then 6 inches now.

05ltdhemi 07-01-2012 06:54 PM

Re: Another DIY CAI
 
^ truth. Hydrolock is not a nice friend to have!

suzieque 07-01-2012 07:08 PM

Re: Another DIY CAI
 
I like it, nice job! I've looked at that area and wondered about an intake. There is an after market can for gm trucks that utilize that design but the cost of it was in the hundreds, to rich for me to buy and test with.

SweetWilliam 07-01-2012 07:33 PM

Re: Another DIY CAI
 
Very mindful of the water thing. Curious to see if it makes any difference on my 150 mile round trip to work tomorrow. In a few weeks I will be working down by Louisville, 6.5hrs from home. I'm going to try all the cheap old and new school things I can think of to bump mpg. Knew what i was getting when I bought it but that doesnt mean I'm not going to see what I can get out of it. Unless I get bored of the street look and decide to lift it. I do miss my XJ.
Got about $20 and a couple hours messin around into it. If it doesnt help then I will find another stock aibox and work on getting a little more air into stock hole and move on.

jeepgcoman 07-01-2012 09:44 PM

Re: Another DIY CAI
 
SweetWilliam, I think you're on the right track. IMO, you're right about the aftermarket CAI's. I built CAI's for both my Hemi WK and Hemi LX, so here are a few things I did when building mine, and also a few recommendations for you, FWIW.
--First, on yours, Madanio24 is correct, but if you left the stock inlet in the front of the airbox, it probably won't be a problem, as that inlet is probably 3.5 feet off the ground. In deep water, the air will be drawn from the top one (path of least resistance), not the bottom one.
--If you're running the lower tube in a "loop" (say, down and then up behind the grill), be sure to punch a little hole in the tube at the lowest point, so any water/moisture that accumulates at the low point can be drained.
--Your screen on the fascia won't do much except keep boulders and small animals out. I tried mine, both with and without some sort of filtering, and ended up with nothing covering the openings. True, I do have to clean the bottom of the airbox (below the filter) more frequently, but nothing is getting into the engine. I just found the other way to just be more trouble than it was worth.
--On both my vehicles I have two inlets to the airboxes, one on the bottom and one in front. The ones in the front are located as close to the bottom of the filter as possible. This gives maximum height in the event of high water. Get higher than that and you're doomed anyway.
--The inside of the tubing (airbox to throttle body) should be as smooth as possible, preferably without ridges/ribs or sharp corners/edges. You want to avoid any and all air turbulence in the tube, if possible. Kind of tough to do going into the box, but not so from the box to the throttle body. Remember, an engine is just a big pump, and the stock airbox is capable of moving just under 700 CFM of air, but a stock/relatively stock 5.7 Hemi is only capable of processing around 600 CFM at maximum RPM.
--On my WK, using a modified LX SRT airbox, I had to adapt an extension to the stock SRT LX intake tube. I used a piece of 4 in. ABS (yes, Home Depot is great), and chamfered the ends of it on the inside, so it would move the air with as little turbulence as possible. I've even tapered (rounded) the inlet to the throttle body a little.
--If possible, from the airbox to the throttle body, run a tapered tube. To a small degree it will act as a venturi and increase the air speed as it enters the throttle body. On my LX I have a double walled, insulated, tapered (4 in. to 3.25 in.) hose. The second (outer) wall is 5 in. On the WK, it is tapered the same as the LX, since it is basically the same setup, without the double wall. I am also using the stock, ribbed tube, which I am sure creates a little problem with airflow.
--Go to the dealer and purchase a Challenger Intake Air Sensor. It samples the air from the middle of the tube, vs. the stock one, which samples the air closer to the outer wall.
--Use either a K & N or TruFlow air filter. I use a K & N on the WK and a TruFlow on the LX. Just wanted to try them both.....and both seem to work about the same.

I think that's about all of my findings. If I think of something else, I'll post it up. Good luck, and keep on tinkering.

dmsfun 07-02-2012 08:24 AM

Re: Another DIY CAI
 
Welcome to the WK Hemi world. First thing before CAI testing or any modding at all, is to get the Hemi running like it did new so you have a baseline to work from. IF you have over 60-70k, I'd put in new EGR and MAP sensor. The TB gets very gunked up on Hemi's unless there is a catch can installed, so the first thing I would recommend is install a Billet tech catch can, then clean the TB, then run Seafoam through the tank, and crankcase. If you have a Hemi tick, which most do, I found it is due to sticking MDS lifters, and Seafoam cures that, also mkaing the throttle response a lot better. Mine has no ticking at all with 80k, and it runs miuch better than new. If you want worthwhile upgrades, don;t worry about a CAI; a CNC ported 85 mm TB, and Apexi super voltage stabilizer makes it respond really well at all RPM.

SweetWilliam 07-02-2012 06:03 PM

Re: Another DIY CAI
 
Thanks for the info.
I have a question about the throttle body. I see that boring them to 85mm is popular. Question is has anyone tried taper boring? I read something on here about velocity VS volume which is right on in my book. I learned a lot seeing how a high strung 450 class 4stroke motor reacts to small changes. Wasnt seat of the pants or "I spent X amount of $ on the greatest hyped Kanooter valve and of course I make twice the power" (reality was usually twice the noise/money/half the durability), it was done back to back runs on the same dyno with AFR meter. Carbs bored out to 43mm often resulted in worse midrange power than a stock 38mm. Taper bore the same carb and pick up power across the entire RPM range. A bike that seems to run fine wil pick 2-5 hp with correct jetting by using the AFR meter and dyno as tools.
We use aluminum tube for an intake also. Was interesting to see the changes on the graph when we cut a halh inch off the tube. Every motor had a sweet spot. More power can be made with some epoxy on the outside of the radius inside tube. Air doesnt like to change directions. Faster moving air will make it around a open valve face quicker than a bigger, slow moving charge. High Velocity Porting rules!
So my next move is a cheap aluminum tube from the parts store, some epoxy, and insulation from Summit...
And some more studying on this catch can thing I have seen mentioned before.

FlyinRyan 07-02-2012 11:56 PM

Re: Another DIY CAI
 
I also come from a ATV/MX background.

I do taper porting by hand on the TBs. It's been very effective, see Itrader, vendor feedback, etc.

I also have used epoxy to fill floors in manifolds, etc.





Quote:

Originally Posted by SweetWilliam (Post 650939)
Thanks for the info.
I have a question about the throttle body. I see that boring them to 85mm is popular. Question is has anyone tried taper boring? I read something on here about velocity VS volume which is right on in my book. I learned a lot seeing how a high strung 450 class 4stroke motor reacts to small changes. Wasnt seat of the pants or "I spent X amount of $ on the greatest hyped Kanooter valve and of course I make twice the power" (reality was usually twice the noise/money/half the durability), it was done back to back runs on the same dyno with AFR meter. Carbs bored out to 43mm often resulted in worse midrange power than a stock 38mm. Taper bore the same carb and pick up power across the entire RPM range. A bike that seems to run fine wil pick 2-5 hp with correct jetting by using the AFR meter and dyno as tools.
We use aluminum tube for an intake also. Was interesting to see the changes on the graph when we cut a halh inch off the tube. Every motor had a sweet spot. More power can be made with some epoxy on the outside of the radius inside tube. Air doesnt like to change directions. Faster moving air will make it around a open valve face quicker than a bigger, slow moving charge. High Velocity Porting rules!
So my next move is a cheap aluminum tube from the parts store, some epoxy, and insulation from Summit...
And some more studying on this catch can thing I have seen mentioned before.


dmsfun 07-06-2012 12:02 PM

Re: Another DIY CAI
 
Taper bored 85 mm TB is a winner for the Hemi. No minuses. I have one tested it with both stock and CAI. Works best with the stock air intake for best torque and overall throttle response.

S10slayer 07-06-2012 12:09 PM

Re: Another DIY CAI
 
Pretty sweet!

SweetWilliam 07-06-2012 07:22 PM

Re: Another DIY CAI
 
After 4 days of 130 miles a day at 75=80mph on the highway, the WK is up 1.5mpg or so. Nothing exciting but an improvement. Looks like I will be making this drive for a while so any improvement is good news.
Want to do some work on an intake tube but taking off on the Harley in the morning so that will have to wait another week.


All times are GMT -5. The time now is 04:02 PM.

Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community